Method of making tubular corrugated walls



June 29 1926.

J. V. GIESLER METHOD OF MAKING TUBULAR CORRUGATED WALLS Original Filed p 13, 1921 3 Sheets-Sheet 1 II N June 29 1926.

J. V. GIESLER METHOD OF MAKING TUBULAR CORRUGATED WALLS Original Filed P 13. 1921 5 Sheets-Sheet 2 gwuantoz l I I f 1 I H h l l l l l ifl U J bm I $1 2% G MmL Lm June 29,1926. 1590337 J. V. GIESLER METHOD OF MAKING TUBULAR CORRUGATED WALLS Original Filled p 13. 1921 3 Sheets-Sheet 5 5F 42 1;; W W

Patented June 29, 1926.

UNITED STATES P ATE NT OFFICE.

JEAN V. GIESLER, OF KNOXVILLE, TENNESSEE, ASSIGNOB TO THE FULTON COMPANY,

OF KNOXVILLE, TENNESSEE, A CORPORATION OF MAINE.

'unrnon or MAKING TUBULAR oonn'uen'rnn warms.

Original application filed September 18, 1821, Serial No. 500,838. Divided and this application filed December 8, 1924.

This invention relates to combined floats and'thermostats and, while applicable to a variety of devices, has special reference to combined floats and thermostats for controlling an air valve, such as is commonly applied to a steam radiator to permit the escape of air but prevent the escape of steam or water. The present application is a divi sion of my application for Combined float and thermostat, Serial No. 500,336, filed I September 13, 1921.

Heretofore air valves of this character have .been commonly provided with separate float and thermostatic elements which, in some cases, have been connected to form a unit. Devices of this character, however, have the serious objection that they are more or less complicated in construction and expensive to manufacture and the use of separate float and thermostatic elements frequently entails the consumption of so much space as to render use of the device imprac-. tical.

To overcome the disadvantages incident to the provision of separate float and thermostatic elements,' it has been suggested to provide a combined float and thermostat by constructing a buoyant element of material which will expand and contract in response to temperature variations to actuate the valve member. Devices of this. character, however, have not proved satisfactory for a number of reasons, among the more im ortant of which is the relatively great 5 uggishness or thermostatic lag incident to the operation of an element which depends upon volumetric or linear expansion to effect the opening and closing of a valve.

It has also been roposed to provide a combined float and t ermostat in the form of a hollow buoyant body having a diaphragm soldered or brazed into one end thereof and charged with a'volatile fluid which, by change of vapor tension when subjected to the temperature of steam, will flex said diaphragm and actuate the valve member. Devices of this character have also proved unsatisfactory for a numberof reasons, among the more important of which is the fact that the flexure of said diaphragm necessarily produces repeated and oppositely-directed stresses at the soldered or brazed joint, so that said joint opens after a shortperlod 0t use with the consequent Serial No. 754,823.

leakage of the volatile fluid and inoperativeness of the device.

It is an object of this invention to provide a combined float and thermostat, particularly designed. for controlling an air valve, which employs an expansible and contractible hollow buoyant member having a flexible wall while avoiding the danger of rupture and leakage incident to flexure at a soldered or brazed joint.

Another object of this invention is to provide a device of the type characterized which is possessed of relatively great buo ancy for the space which itoccupies. Anot or object of this invention is to provide a device of the type characterized wherein the hollow buoyant member has a flexible wall which is highly sensitive to the actuating force of the thermosensitive medium contained within said member.

Another object of this invention is to provide a device of the type characterized which emplo s a. minimum number of soldered or braze joints; also one that is composed of a minimum number of simple parts that are easy to manufacture and assemble; also one that is compact in structure and highly efficient in operation.

Another object of this invention is to provide a method of manufacturing buoyant members of the type characterized which employs relatively few and relatively simple steps, so that the device may be inex pensively manufactured in large quantities -wi-thout the use of costly machinery or highly'skilled labor.

Another object of this invention is to provide a method of manufacturing a device of the type characterized whereby said buoyant member may comprise a lateral integral wall which has been rendered highly flexible. Another object of this invention is to provide a method of manufacturing a device of the type characterized which comprises a lateral integral wall so shaped as to afford relatively great buoyancy for the space which the device occupies. Otheriobjects will appear as the description of the invention proceeds.

Stated broadly, the invention comprises a combined thermostat and float, articularly for use in anair valve, composed of a closed hollow buoyant member having a flexible lateral wall and. charg th a theme:

sensitive medium, preferably a volatile fluid. The flexibility of said lateral wall is preferably afforded b providing said wall with a exible corrugations which plurality ''of extend for only a portion of the length of said lateral wall, and the uncorrugated ortion of said wall is referably enlarge so that its cross-section is at least equal to the approximate maximum cross-section of said corrugated portion. The invention also comprises the method of manufacturing a buoyant memberof this character so that the corrugated and uncorrugated portions of its lateral wall may be formed integrally from one tubular icce of material, and the enlargement o the uncorrugated' portion, if desired, and also the forming of the corrugations, may be readily effected by interior radial pressure, aided preferably by a longitudinal force of compression.

The invention is capable of receiving a variety-of mechanical expressions and being carried out. in a variety of ways, some of which are shown on the accompanying drawings, but it is to be expressly understood that the drawings are for purposes of illustration only and are not to be construed as a definition of the limits of the invention, reference being had to the appended claims for that purpose.

Referring in detail to said drawings Fig. 1 is-an axial section of an air valve suitable for application to a steam radiator and embodying the present invention;

Fig. 2 is an axial section on a somewhat reduced scale of another air valve also embodying the present invention and illustrating the combined float and thermostat in ex panded condition; and

Figs. 3, 4, and 5, are somewhat diagrammatic axial sections of suitable apparatus for carrying out the method of this invention and illustrating successive steps in the performance of said method.

In the form shown in Fig. 1, the valve casing 10, of any suitable form and construction, is providedwith inlet and outlet connections, 11 and 12 respectively, threaded for attachment to a radiator or other suitable device. Said casing adjacent the, top thereof isprovided with an air vent 13, shown as' an axial aperture formed in athreaded plug 14 which is received, and preferably soldered,'within a threaded aperture in the top of said casing. A cap 15 of any suitable, construction, through the wall of which extends one or more apertures 16, may be mounted on the casing 10 over the vent 13, if desired, for purposes of appearance and protection. The axial aperture constituting the vent 13 is shown as enlarged at its lower end 17 and provided with a conical seat 18 intermediate its sections of different diameter, whereby there is provideda valve seat for the valve member to be described.

The threaded plu 14 may also carry, if de sired,-a baflle or efiector plate 19 adjacent its lower end.

The valve member 20, in the form shown,

is composed of an elongated stem or rod hav- (0 ing a conical end 21 for coaction with the conical seat 18, and provided adjacent its lower end with a flange or collar'22 by which said valve member may be secured in any suitable way, as by soldering or brazing, to the top of the combined float and thermostat 23.

Said combined float and thermostat, in the to the end corrugation, as by soldering or brazing. In the preferred embodiment of this invention, the uncorrugated portion of the lateral wall is relatively long as compared to the corrugated portion and at'least as large in cross section as the maximum cross section through the corrugated portion, so that the corrugated portion of said lateral wall is approximately contained within the cylindrical surface defined by the uncorrugated portion of said wall; if desired, however, sa'id uncorrugated portion may be made of even greater cross section than the maximum cross motion through the corrugated portion.

The hollow closed member thus provided is preferably supplied with means to limit the extent to which said member may be contracted and, as said member is also preferably rovided with a tube for introducing a t ermosensitive medium into'the interior thereof, said filling tube is preferably elongated to provide a stop for the con-, traction of said hollow member. In the form shown, a filling tube 28 is brazed or otherwise suitably secured in an aperture 29 provided in the end wall 27 and extends to a free end 30 in position to engage the endwall 25 of the hollow member and limit the contraction of said member, Said tube is also preferably provided with a vent opening 28 to permit the escape of air when the hollow member is being charged with thermosensitive medium. Said closed hollow member is charged with a thermosensitive medium preferably a small quantity of a volatile liquid having a boiling point at or adjacent to the temperature of steam, said thermosensitive medium being introduced through the filling tube 28 after which said tube is sealed by a plug 31 of any suitable material preferably soldered in the outer end of said tube.

The lower wall ofthe casinglO is shown as provided with an upstanding and transversely slotted rib or projection 32 upon which the combined thermostat and float is normally seated and, if desired, a centering plate or spider 33, shaped to conform generally with the interior cross-section of the casing 10 and preferably provided with apertures 33, may he soldered or otherwise suitably attached to the end wall 27 of the combined float and thermostat to constitute a centering device for the lower end thereof.

In practice. the inlet 11 of the casing 1.0 is suitably connected to the upper portion of a radiatorand the outlet 12 is suitably connected to a lower portion of said radiator. \Vhen steam is first turned into the radiator. the air is displaced thereby and may flow into the casing 10 and escape throughthe vent 13, the valve member 20 being spaced from the port 18 because the combined thermostat and float 23 is then in contracted position and seated on the projection 32. As soon as the air is driven out of the radiator, the steam flows into the casing 10 through the inlet 11 and is deflected downwardly into the lower portion thereof by the baflie or deflector plate 19. The temperature of this steam promptly increases the vapor tension of the volatile fluid confined within the hollow closed member 23, and said member expands owing to the flexibility of its lateral wall afforded by the corrugations 26 and engages the conical end 21 of the valve member 20 with the conical seat 18 in the air vent 13 to prevent the escape of steam. This action is effected promptly owing to the sensitive response of the vapor tension of a volatile liquid to temperature changes and to the relatively great flexibility afforded by the relatively deep corrugations 26. Valve member 20 will then be held in engagement with the seat 18 and prevent the escape of steam as long as steam enters the valve casing 10. If, on the other hand, water enters said valve casing 10, as occurs for example when a radiator becomes waterdogged. the escape of water through the vent 13 is prevented because the hollow buoyant member 23 rises with the water until the conical end 21 of the valve member engages the seat 18, and will remain in this position as long as the water remains in the casing 10. This action is insured by the relatively large buoyancy afforded by' a closed hollow member of the form and capacity provided by the present invention. In this elevated position of the combined float and thermostat, the aperture through the outlet 12 is wide open so as to permit the water to drain back into the system at the first opportunity. \Vhen the temperature in the interior of the casing 10 is reduced below that of the steam, the vapor tension of the volatile fluid in the combined float and thermostat-23 is corre spondingly reduced, and said. m mber 23 may contract, owing to the resiliency inherent in the flexible corrugations when the wall is made of resilient material, until the end wall 25 engages the stop afforded by the free end 30 of the tube 28.

from the valve seat 18 if the casing 10 is also substantially free of water, so as to permit the passage of air through the vent 13.

In the form shown in Figure 2, the valve casing 10 is provided with an inlet connection 40 at its lower end and the outlet connection is allorded by a long curved tube 41 which is smaller than the inlet 40 so as to provide a tree passage for the air, steam and water through the annular space surrounding said tube 41. Said tube may be mounted in any suitable way, as by securing the same in a boss 42 extending upwardly within the lower end of the casing, and projects downwardly into the radiator or connections for a suitable distance to insure that the water will drain from the casing. In this form of the invention, said boss 42 is shown as provided with a recess 43 which coacts with the outwardly pupjecting end of the filling tube 28 to center tie combined float and thermostat within the casing 10, said boss also constituting a seat for said combined float and thermostat when the casing is substantially free from water. Otherwise the construction of Fig. 2 is substantially the same as that illustrated in Fig. 1, corresponding parts being indicated by the same reference characters.

In manufacturing said combined float and thermostat, I preferably make the lateral wall of the buoyant member, including both the corrugated and the uncorrugated portions thereof, from a single piece of integral tubular material, and also preferably form one end wall of said member integrally with said lateral wall, by subjecting a tubular blank interiorly to re ial pressure and also, preferably, to a simultaneous longitudinal force of compression. A suitable apparatus for carrying out this method with the use of hydrostatic pressure is illustrated diagrammatically in Figs. 3 to 5, wherein 50" designates a form or die providing an elongated recess having a plurality of corrugations 51 and an enlarged uncorrugated cylindrical section 52. Said form may be made in two or more sections retained. in position by rings driven onto the tapered exterior of said sections and locked in alignment by one or more transverse pins 71. Within said enlargement 52 works a. head 53 shaped at ,its inner face 54 to conform with the shape to be given the The conical end 21 of the valve member is thereby withdrawn end wall of the buoyant member heretofore operating wheel 57. A suitable plunger 58 is mounted to reciprocate within the aforesaid recess provided by the form or die 50,

and carries at its inner end a cup leather 59 for engagement with the interior of a tubular blank 60 having an integral end wall 61, which is to be shaped within said form. Said plunger 58 is shown as provided with a passage 62 extending through its inner end and communicating with piping ,63 leading from any suitable source of hydrostatic pressure. Said plunger is also provided with a plurality of transverse apertures 64 designed to receive a pin 65 which constitutes an abutment for said plunger by coaction with the frame 66 of the apparatus.

In conformity with the preferred procedure of this invention, the tubular blank 60 is positioned in the form or die with its end wall 61 in engagement with the convex face 54 of the head 53, as illustrated in Fig. 3. Hydrostatic pressure is then admitted to the space within the blank between its end wall 61 and the end of the plunger, and said blank is forced outwardly or expanded so as to assume the shape of the cavity between the convex face 54 of the head 53 and the end of the enlargement 52, as illustrated in Fig. 4. The head 53 is then withdrawn a short distance, as b manipulation of the wheel 57 and threa ed stem 55, and the blank is advanced a corres nding distance into the form in any suitab e way,'as by the action of h drostatic pressure on the end wall thereo to the position shown in Fig. 4. Hydrostatic pressure is again admitted to the s ace between the end wall 61 and the end of t e plunger and, to aid the expansion of the blank without unduly stressing the material, wheel 57 is preferably manipulated simultaneously to move the head 53 toward said blank and exert a longitudinal force'of compression on said blank. By the combined action of the radial pressure and longitudinal force of compression, the section of the tubular blank projecting into the enlargement 52 is forced outwardly or expanded to the shape of the space between the head and the plunger, as illustrated in Fig. 5. The head 53' is then moved rearwardly another short distance, the blank again advanced until. it engages said head, and. the tubular blank is again expanded by the radial action of hydrostatic pressure and the longitudinal force of compression. This is repeated'successively until said tubular wall is enlargedto the desired portion of its length.

If the change in cross section of the tubular blank is relatively large, said enlargement may be efiected progressively by successive treatments of the blank in forms having enlargements of progressively increasing cross section and, if desired, said well may be annealed b twe n each successive treatment thereof to remove more or less of the effects of cold working.

The blank with. its enlarged portion may then be removed from the form and corrugations ,rovided in the unenlarged portion of the. lank in any suitable way, but I preferabl form the corrugations, or at least the initia corrugations, in the blank before it is removed from the form or die. This is accomplished in the apparatus illustrated by successively withdrawing the plunger 58 within the blank so as to uncover successively the sections. of said blank opposite the successive corrugations in the wall of the form, and then introducing hydrostatic pressure to the interior of the blank to force the succeeding sections of said blank into the successive corrugations of said form. In carrying out this part ofthe method the in is introduced into the successive ho cs 64 to properly position theplunger 58 in its successive positions to uncover the successive corrugations of the form. This part of the method may be carried out in conformity with the method disclosedand claimed in the patent of Weston M. Fulton and myself, No. 1,522,051, dated January 6., 1925, and entitled Corrugated walls and methods of making the same, to which reference is made for a more detailed explanation of the referred process of forming corru ations in a tubular blank by the action of ydrostatic pressure and, if desired, the simultaneous action of a longitudinal force of compression; After the blank is removed from the form the corrugationsmay be subjected to one or more rolling operations or other suitable treatment, if desired, to deepen and narrow the corrugations or otherwise suitably impart so that the use of a flexible'diaphragm has I been avoided, the necessity for flexure at a soldered or brazed joint eliminated, and the danger of premature rupture and leakage overcome. At the same time, a combined float and thermostat has been provided in which the buoyant member is possessed of relatively great flexibility so that it may be readily expanded and contractedto effect the purpose for which it is designed. Furthermore, by, providing an uncorrugated portion which. is at least as large in cross section as the maximum cross section through the corrugated portion, said hollow member is possessed of relatively great buoyancv because of its large interior capacity; 7 inasmuch as the interior of the valve casing must be made at least as large as the outside diameter of the corrugations, said hollow member affords a maximum buoyancy forthe space which it must occupy. Additionally, the loss of buoyancy incident to the increase in weight necessarily accompanying the application of solder to a plurality of joints has been avoided.

At the same time, it will be perceived that a method of manufacturing a buoyant member of this character has been provided whereby the lateral wall with its flexible corrugations and its enlarged uncorrugated portion, and also one end wall if desired, may be made integrally from a one-piece tubular blank by a minimum number of simple operations. Moreover, a method of manufacturing said member has been provided whereby the tubular blank may be enlarged without danger of rupture or undue stressing of the materialas might occur if the enlargement were efi'ected by the action of hydrostatic pressure alone-and also a method by which the enlargement of the blank and the forming of corrugations in the unenlarged portion thereof may be successively and readily effected in a single apparatus.

While the embodiments of the invention illustrated on the drawings have been described with considerable particularity it is to be expressly understood that the invention is not limited thereto. as the invention is capable of being embodied or carried out in a variety of ways, some of which will now readily suggest themselves to those skilled in the art, while changes may be made in the sizes, portions and details of construction and procedure without departing from the spirit of this invention. While the corrugated portion of the combined float and thermostat has been shown as positioned at the lower end thereof, such is not, essential, as the device would still be possessed of marked utility if it were inverted and the -valve member attached to the corrugated end, or'

if the corrugations were disposed intermediate the ends of the lateral wall. The apparatus illustrated for carrying out the method of'this invention may also be modified in many respects, and rendered automatic if desired, while the interior force of enlargement and the longitudinal force of compression may be obtained simultaneously from a common source of power without departing from the spirit of this invention.

Reference is therefore to be had to the claims hereto appended for a definition of the limits of said invention.

What I claim is 1 1. In the method of manufacturinga hollow buoyant member, subjecting a tubular wall having a closed end to interior h drostatic pressure to enlar e said wall orfla portion of its length a jacent said closedend, and forming corrugations 111 the unenlarged portion of said wall.

'larged portion of said wall..

2. In the method of manufacturing a hollow buoyant member subjecting a tubular wall to interior hydrostatic pressure for a portion of its length to provide an enlarged uncorrugated portion, and forming corrugatlilons in the unenlarged portion of said wa 3. In the method of manufacturing a hollow buoyant member, subjecting a tubular wall interiorly and successively to hydrostatic pressure for a portion of its length to provide an enlarged cylindrical portion, and forming corrugations in the unenlarged portion of said wall.

4. In the method of manufacturing a hollow buoyant member, subjecting successive sections of a tubular wall interiorly to hydrostatic pressure to provide an enlarged uncorrugated portion, and forming corrugations in the unenlarged portion of said wall.

5. In the method of manufacturing a hollow buoyant member, subjecting a tubular wall havinga closed end simultaneously" to interior hydrostatic pressure and a longitudinal force of compression to enlarge said 90 wall for a portion of its length, and forming corrugations in the unenlarged portion of said wall.

6. In the method of manufacturing a hollow buoyant member, subjecting a tubular 95 wall having a closed end successively to simultaneous applications of interior hydrostatic pressure and a longitudinal force of compression to enlarge said wall. for-a portion of its lengthby progressive increments, and forming corru ations in the unenlarged portion of said wa 7. In the method of manufacturing a hollow buoyant member, subjecting successive sections of a tubular wall to simultaneous applications of interior hydrostatic pressure and a longitudinal force of compression to provide an enlarged uncorrugated portion, and forming corrugations in the unen- 8. In the method of manufacturing a hollow buoyant member, subjecting a tubular wall having a closed end interiorly to hydrostatic pressure to enlarge the same for a portion of its length, and forming corrugations by ydrostatic pressure in the unenlarged portion of said walls 9. In the method of manufacturing a hollow buoyant member, subjecting a tubular wall simultaneously to interior hydrostatic 12 pressure and a longitudinal force of compression to provide an enlarged cylindrical-1" portion, and forming corrugations by by drostatic pressure in the unenlarged portionof said wall. y

10. In the method of manufacturing a hollow buoyant member, subjecting a tubular wall having a closed end to pressure to enlarge the same for a portion of its length, confining said pressure to the portion of the wall to be enlarged, and forming corrugations in the unenlarged portion of said wall.

11. In the method of manufacturing a ho].- low buoyant member, subjecting a tubular wall, to pressure to provide an enlarged uncorrugated portion and forming in the unenlarged portion of said wall corrugations which are not substantially larger in outside diameter than the diameter of said enlarged portion.

12. In the method of manufacturing a hollow buoyant member, positioning a tubular wall having a closed end in a form having a regionof enlarged cross section, enlarging a portion of said'wall by expanding the same into said region of enlarged cross section, and forming corrugations in the unenlarged ortion of said wall.

13. In the met 0d of manufacturing a hollow buoyant member, positioning a tubular wall having a closed end in a form having a region of enlarged cross section, enlarging successive portions of said wall by expanding the same into said region of enlarged cross section until said wall is enlarged for the desired portion of its length, and forming corrugations in the unenlarged portion of said wall.

14. In the method of manufacturing a hollow buoyant member, positioning a tubular wall in a form havmg a region of en larged cross section, subjecting said wall simultaneously to interior radial pressure and a longitudinal force of compression to expand a portion of said wall into said re ion of enlarged cross section and to provi e an enlarged uncorrugated portion, and forming corrugations in the unenlarged portion of said wall.

15. In the method of manufacturin a hollow buoyant member, positioning a tu ular wall having, a closed end in a form having a region of enlarged cross section, subjecting successive portions .of said wall simultaneously to an interior radial pressure and a longitudinal force of compression to expand the same into said region of enlarged cross section until said wall is enlar ed for the desired portion of its len h, an forming corrugations in the unen arged portion of said wall.

16. In the method of manufacturing a hollow buoyant member, positioning a tubuexpanding a portion of said wall by hydrostatic pressure into said region of enlarged cross section, and then successively forcing said wall by hydrostatic pressure into the successive corrugations of said form.

17. In the method of manufacturin a hollow buoyant member, positioning a tu lmlar wall in a corrugated form having an uncorrugated region of enlarged cross section, simultaneously subjecting said wall to interior hydrostatic pressure and a longitudinal force of compression to expand a portion of said wall into said region of enlargedcross section, and then successively subjecting the sections of said wall opposite the successive corrugations in said form to said interior hydrostatic pressure to form corrugations in the unenlarged portion of said wall.

18. In the method of manufacturing a hollow buoyant member, positioning a tubular wall'in a corrugated form having an uncorrugated region of enlarged cross section, and successively subjecting said wall to the combined action of interior hydrostatic pressure and a longitudinal force of compression to expand successive portions of said wall into said region of enlar ed cross section and the successive corrugations of said form.

19. In the method of manufacturing a combined float and thermostat, subjecting a tubular wall to pressure to enlarge its cross section for a portion of its length, forming corrugations in the unenlarged portion of said wall, closing the open end or ends of said wall to form a closed hollow member, and sealing a thGImbSGIISitiI G medium in said hollow member. 20. In the method of manufacturing a combined float and thermostatfor an. air valve, subjecting a tubular wall to pressure to enlarge the same in cross section for a portion of its length, forming corrugations in the unenlarged portion .of said wall, closing the open end or ends of said wall to form a closed hollow member, sealing a thermosensitive medium in said hollow member. and attaching a valve member toonc end of said hollovs member.

In testimony whereof I have signed this specification.

JEAN V. GIESLER. 

